Crewless glider



Sept. 25, 1945. w VAN DUSEN 2,385,392

CREWLESS GLIDER Filed June 14, 1944 INVENTOR Anueewcis 14 (44 065 Patented Sept. 25, 1945 2.385.302 caawmss amen Laurence w. Van DnsemTuclon, Aria. Application June 14, 1944, Serial No. 540,2

4 Claims. (01.244-3) (Granted under the act or March 3, 1883, as

' amended April 30, 1928; 310 0. G. 757) UNITED smes perm The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to gliders, and more particularly to a crewless glider adapted to be towed by an airplane.

It is common practice at present to tow gliders from airplanes in which the towed glider is either controlled by a pilot in the glider, or is guided by manual controls actuated from the tow airplane by the pilot thereof. It Will be apparent that if a glider were built with a lower factor of safety it could be built both cheaper and lighter for any given pay load." Where there is no glider crew necessary, such a low safety factor becomes possible since, in case of emergency, the glider could be jettisoned without endangering life, the only loss being the glider and cargo, Furthermore, elimination of the glider pilot would enable the glider to carry additional pay load equal to the weight of the pilot plus the weight of any special equipment which may be provided for his safety and comfort.

One object of the present invention is to provide a crewless glider which will automatically follow the tow airplane.

Another object is to reduce the factor of safety used in building gliders.

A further object is to provide a crewless glider in which the controls are automatically actuated to conform to movements of the tow plane.

A still further object is to provide a glider that can be jettisoned without risking personnel.

Still another object is to reduce the cost of gliders.

Another object is to provide a glider which will carry a greater dead load than gliders now being made.

Other objects will become apparent upon considering the following specification, which, when taken in connection with the accompanying drawing discloses two forms of the invention.

In its broad aspect, the invention comprises a crewless glider towed by a tow plane, with the connecting means Joining the tow plane with the glider automatically operating the controls of the glider to cause the glider to follow the tow plane.

In the drawing:

Fig. 1 is an elevational view of a tow plane, a glider, and the tow bar connecting the two;

Fig. 2 is a cross-sectional elevational view through the head of the glider;

Fig. 3 is a view partly in cross-section through Fig. 4 is a plan view of a modified form of the invention: and

Fig. 5 is a cross-sectional elevational view through the glider wing showing the control illustratedinl'ig. 4. g

Referring first to Figs. 1. 2, and 3, a tow plane, generally designated ll, may comprise a body Ii, wings I2, a tail structure II, and one or more motor nacelles II which contain engines (not shown) to drive propellers it.

The end or the tail structure It is provided with a universal joint ll, shown in detail in Fig. 3, which supports the tow bar 2| and secures it to the airplane. The bar 2| is preferably made tubular to lend the requisite stiffness, and of light weight material to cut the weight to a minimum.

The tow bar 28 joins the tow plane II with a glider, generally designated 25, in a manner more fully set forth below. The glider may comprise a body It, wings 21 having ailerons II, a landing gear Ill-4|, and a tail comprising a vertical rudder 33 and an elevator II.

The control of the rudder, the elevator, as well as the ailerons, is eflected through a universal connection 3| which joins the tow bar II to the glider I5.

As best seen in Fig. 2, the universal connection it comprises a tube ll mounted for rotation in the nose ll of the glider 25. The tube ll, while free to rotate in the nose II, is restrained from longitudinal movement by a bearing 43. The tube 40 may carry a pair of control horns 4| fixed thereto to rotate therewith. Control cables (not shown) are connected to apertures "-48 in the ends of the horns l5 and actuate the ailerons 28 in the usual manner.

The outer end or the tube 40 carries a. universal joint II, which comprises a yoke SI having a collar II pivotally mounted in the outer end. A pair of pins II are pivotally mounted in the collar II and on an axis at right angles to the pivotal axis of the collar ii. The pins 52 carry the tow bar 2|, which has, as a result or the joint I, a universal movement relative to the nose I of the glider ii.

The glider end of the tow bar 20 has control cable mountings "-55 fixed on the top and bottom thereof and a second pair of control cable mountings I at right angles thereto, the cable mountings I! being in alignment with the axis of the collar ll while cable mountings II are slightly spaced from pins 52 though in the same horizontal plane. Control cables 58-48 are connected to the cable mountings 88-55 and pass through the tube 88 to the elevator 88 to control the elevation of the glider 25. The cables 88-58 may pass over one or more guide pulleys 88 between the ends of the tow bar.

Similarly cables 88 join the tow bar 28 with the vertical rudder 88 through the cable mountings 58, with one or more guide pulleys 8| being placed where necessary in order to insure the cable working freely. The cable 88 controlsthe rudder 88 and hence the direction of the glider in a horizontal plane.

Referring to the form of the invention shown in Figs. 4 and 5, a tow plane I8 may comprise a body II, having a wing I2 fixed on the forward end and a tail structure It on the rear or trailing end thereof. The wing may carry one or more motor nacelles ll-I8 containing motors which drive propellers 15-15. Ailerons I8-I8 are formed on the outer trailing ends of the wing 12 to impart a rolling motion to the airplane. The tail structure 18 includes an elevator 18 and a vertical rudder I8.

The plane I8 may tow a glider 88, which is both towed and automatically controlled in a manner to be described below, through a plurality of cables 82-82, and 88-88.

The glider 88 may comprise a body portion 85 adapted to carry a cargo, a wing or wings 88 and a tail 81 which may consist solely of a horizontal stabilizer.

The wing 88 is provided with ailerons .88-88 at the outer ends thereof, the ailerons also acting simultaneously to serve as elevators for the glider. The movement of each of the ailerons is controlled by a pair of control horns 88 fixed to each aileron and projecting from opposite sides thereof so that turning the horns 88 through any angle causes the aileron to turn through a corresponding angle.

The extremities of the control horns 88 are connected 'by links 82 and 88, re'spectively, to the extremities of tow horns 85-88. The tow horns 88, which may be joined or integral, as shown, are pivotally mounted near the forward or leading edge of the wing 88 and at the center thereof, as indicated at 88.

The tow ropes 82-82 ar connected from the trailing edges of the tow plane to the lower ends of the horns 85-85, while the tow ropes 88-83 are connected to the upper ends of the horns 88-85. Operation In the form of the invention shown in Figs. 1, 2, and 3 the glider 25 is attached to the tow plane I8 through the tow bar 28 and the plane l8 flown in the usual manner from the field. As the tow plane rises the tow bar slopes downwardly toward the glider, causing the tow bar to rotate about the pivots 52. Movement of the tow bar about the pivots 52 actuates the control cables 58-58 causing the glider to rise and follow the path of the tow plane.

Similarly if the plane makes a horizontal turn, the tow bar 28 causes the ring 5| to rotate on its pivot, which actuates the control cables 88 which actuate the rudder .88. As the plane In banks to make its turn the tow bar rotates, causing the tube 88 to rotate a corresponding amount. Rotating the tube 88 actuates the ailerons 28, causing the wing 21 to tip in accordance with that of the wing of the plane.

In the form of the invention shown .in Figs. 4 and 5, the glider is towed by the tow plane I8 ,at the same elevation as the plane I8 the tension on the cables 82 and 88 becomes equal and the ailerons are returned to level flight position.

As the plane 18 banks one wing is lowered while the other wing is raised. Lowering of the one wing will cause the upper cable 88 on. that side of the plane to exert greater pull than the lower cable 82, thus causing that side of the glider to lower an amount corresponding to the dip of the plane I8. At the same time the rise of the wing on the opposite side of the plane will cause the lower tow rope 82 on that side of the plane to exert a greater pull than the upper rope 88 causing the aileron-to be actuated to raise that side of the glider 88 until the wings of the glider are parallel to the wings of the tow plane.

In turning the plane I8 the plane is banked at the same time that the rudder is actuated to turn the plane. Banking of the plane I8 causes a corresponding banking of the glider 88 as described above while turning of the plane I8 causes unequal tension in both sets of tow ropes 82-83, which causes the glider to turn and follow the plane. The banking prevents side slip and keeps the glider 88 in the path of the plane I8.

It is to be understood that the forms of the invention herein shown and described are to be taken'merely as preferred examples of the same and that various changes in the shape, size, and arrangement of parts may be made as fall within the scope of the appended claims without de- 40 parting from the spirit of the invention.

'What is claimed as new and desired to secure by Letters Patent is:

-1. In combination with a tow plane including a universal joint fixed in the tail thereof, a tow bar joined at one end thereof to said plane through said universal joint, a glider joined to the opposite end of said tow bar, control surfaces on said glider to vary the elevation and direction thereof, and means actuated by a change in the angular relationship between the tow bar and the glider to vary the control surfaces, whereby the glider will follow the tow plane.

2. In combination with a tow plane including a universal joint fixed in the tail thereof, a rigid the tail thereof, a tow bar joined at one end thereof to said tow plane through said universal joint, a glider joined to the opposite end of said tow bar, said glider comprising, a body, wings fixed to said body, ailerons pivotally mounted on said wings. and a tail structure fixed to-said body and adapted to vary the elevation and direction of said glider, means actuated by a change in the angular relationship between the tow bar and the glider to actuate the control suriaces, whereby the glider will follow the tow plane, and means responsive to the angular diiterence between the wing on said towplane and the ring on said glider to actuate the ailerons. v

4. In combination, a tow plane, a glider, a rigid tow bar, universal Joints secured to each end or the tow bar, means securing one oi said universal joints to the tow plane, means securing the other universal joint to the glider, control surfaces on the glider, and cables connecting said control surfaces with the end of the tow bar which is adjacent said glider, so tnatlthe glider will be controlled directly by pull of said cables responsive to movements of the tow plane.

LAURENCE w. VAN DUSEN. 

